News breaks shortly after team re-signed backup King Dunlap, who had been a free agent

Coming off a season in which their starters experienced no major injuries, the Eagles already have been dealt a devastating setback heading into 2012.

The team announced on Friday that left tackle Jason Peters, a four-time All Pro and five-time Pro Bowl selection, has torn his right Achilles tendon and will have surgery on Tuesday to repair it. No word on how long he is expected to be out.

The 30-year-old Peters was coming off perhaps his best season ever, following the the addition of Howard Mudd as offensive line coach. Mudd last season called him the best lineman in the sport.

News of Peters' injury, which happened on Tuesday, broke very shortly after the team announced it had re-signed free agent backup King Dunlap to a one-year deal, indicating a cause-and-effect dynamic was in play. But the team would not comment further, and Peters' agent, Eugene Parker, did not respond to an interview request.

Peters (6-4, 328) was a big reason behind franchise records of 6,386 total yards and 356 first downs and an even bigger reason behind the breakout year of running back LeSean McCoy in 2011. McCoy finished with career highs of 273 carries, 1,309 yards and 20 touchdowns.

Recovery from Achilles surgery typically takes a minimum of six months, which automatically places the first quarter of the season in jeopardy.

The reality is that Peters will start the season on the physically unable to perform (PUP) list and likely will not be ready to go until at least midseason, if at all, in 2012.

"We all know how much Jason loves to play the game and how much he was looking forward to the start of the 2012 season," Eagles coach Andy Reid said. "Jason is one of the best, if not the best, offensive tackles in the NFL. We don't know when he will return to the field and we will not speculate on a timeline. We are just going to let the surgical process and the rehabilitation process play itself out.

"[General manager] Howie [Roseman] and I will sort out the roster situation for the offensive line. We are glad to have King back as a part of our offensive line and we will continue to scan the free agent market, also knowing the draft is less than a month away."

If there is a positive component to this development, it's that it comes while the team still has a chance to fill the potential void, like Reid said.

Among the free agents still available are Marcus McNeill, Demetrius Bell and former Penn State tackle Kareem McKenzie.

A tight end when he first broke into the league in 2004, Peters played at Arkansas alongside former Eagles guard Shawn Andrews, who was drafted in the first round by the Eagles that same year.

Ironically, Andrews spent all of last season out of football and remains a free agent along with his brother Stacy, who played for the Eagles in 2009.

For comparison's sake, the Phillies' Ryan Howard ruptured his Achilles a little less than six months ago and will start this season on the disabled list.

The NFL regular season begins in a little less than six months from now – on the second weekend of September.

Players who start the regular season on the PUP list must sit for the first six games. Teams then have a three-week window in which they can activate those players. Players not activated in that time frame must miss the remainder of the season.